device-lenovo-21bx: Fix typo in lts kernel description

Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/8856>

device/community/device-lenovo-21bx/APKBUILD

@@ -4,7 +4,7 @@
 maintainer="Clayton Craft <clayton@craftyguy.net>"
 pkgname=device-lenovo-21bx
 pkgdesc="Lenovo ThinkPad X13s"
-pkgver=22
+pkgver=23
 pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
@@ -88,7 +88,7 @@ kernel_stable() {
 }
 
 kernel_lts() {
-	pkgdesc="Long-term maintainance kernel (most stability, not all security fixes & new features)"
+	pkgdesc="Long-term maintenance kernel (most stability, not all security fixes & new features)"
 	depends="linux-postmarketos-lts"
 	provides="$pkgname-kernel-any"
 	provider_priority=2